In-situ formed decrystallized interphase enabled high performance all-in-one all-solid-state batteries

Abstract

All-inorganic solid-state batteries (AISSBs) hold great promise as the next-generation energy storage technology, offering exceptional safety and high energy density. However, achieving satisfactory solid-to-solid interfacial contact between battery components presents a significant challenge. An ideal approach is the integration of electrodes with electrolyte to form an all-in-one battery. While feasible using a molten lithium as anode, the cathodic side poses more challenges due to detrimental elemental diffusion during high-temperature treatment. Here, we demonstrate a simple and cost-effective liquid-phase sintering assisted in-situ interfacial growth strategy. This strategy enables the formation of an integrated LiCoO2cathode on Li6.5La3Zr1.5Ta0.5O12 (LLZTO) electrolyte, connected by a unique decrystallizing interlayer. Notably, this interlayer consists of Co-doped LLZTO nanocrystals dispersed in its amorphous matrix (referred to as the NAM area), where the amorphous matrix effectively blocks detrimental elemental diffusion, while the nanocrystals facilitate Li+ transport. Benefitting from this unique NAM structure, the fabricated all-in-one all-solid-state battery exhibits an impressive long cycle life (over 500 cycles at 0.2C). This remarkable cycling performance demonstrates the robustness and reliability of the interlayer. This finding would pave the way for the development of practical AISSBs, offering new prospects in the field of advanced energy storage.